The European Union (EU), as well as Australia and Canada, have also committed to phasing out ordinary incandescent light bulbs over the next few years.
Curry's and Co-op are the first UK retailers to announce that they will no longer stock these bulbs.
Why the change? CFLs are supposedly more energy-efficient and better for the environment than the standard bulb. According to Greenpeace, incan-descent bulbs are inefficient and bad for the climate. CFLs produce the same amount of light, but emit dramatically lower levels of carbon dioxide, a major contributor of global-warming pollu-tion. They also save money-around lb7 ($14) per household per year in the UK, according to Dr Matt Prescott, director of banthebulb.org.
The UK's Green Party MEP Caroline Lucas has estimated that "banning old-fashioned light bulbs across the EU would cut carbon emissions by around 20 million tonnes per year and save between 5 to 8 million euros [lb3.4 to lb5.5 million] per year in domestic fuel bills."
The advantages attributed to CFLs are all to do with the way in which they produce light. Incandescent bulbs heat a filament inside the bulb until it's white-hot, producing the light that you see. Typically, however, about 90 per cent of the energy consumed is converted into heat, not light, thus wasting a lot of energy.
In contrast, fluorescents use a gas that produces invisible ultraviolet(UV) light when the gas is excited by electricity. The UV light hits the white coating inside the fluorescent, which converts it into visible light. Because fluorescents don't use heat to create light, they are far more energy-efficient than regular incandescent bulbs.
However, while fluorescent lighting may be better for the environment, what hasn't been addressed is the potential impact of these so-called 'green' bulbs on people's health.
Effects on health
Ever since their introduction, there has been a great deal of concern that fluorescent lighting may contribute to a range of health issues-from head-aches and eye strain to hyperactivity in children and even cancer.
One major worry is the amount of UV light emitted by these bulbs- significantly more than standard ones. And, although the amount of UV from fluorescents is still considerably less than in sunlight, the fact that many people work under fluorescent fixtures day after day, year in and year out, has stirred fears for the long-term.
Indeed, an early study reported a doubling of the risk of malignant mela-nomas in office workers exposed to fluorescent lighting compared with those occupationally exposed to sun-light (Lancet, 1982; 2: 290-3). Since then, other studies have found a connection between exposure to fluorescent light-ing and malignant melanoma (Am J Epidemiol, 1992; 135: 749-62; Br J Cancer, 1986; 53: 65-74; Lancet, 1983; i: 704).
Yet others, however, found no such association (BMJ, 1988; 297: 647-50; Br J Cancer, 1985; 52: 765-9; Recent Results Cancer Res, 1986; 102: 127-36), and studies that ooked solely at domestic exposure to fluorescent lighting also found no increased risk between fluorescents and skin cancer (BMJ, 1988; 297: 647-50). Nevertheless, with more and more homes adopting fluorescent lighting-even without the government's forcing everyone to do so-there may well be a different picture in the future.
Other health problems are related to flickering. Unlike standard lights, conventional fluorescent light output fluctuates in intensity. While it's not easily seen with the naked eye, some studies hold the resultant 'flicker' to be responsible for headache, eye strain, and reduced reading performance on visual tasks (Ophthalmic Physiol Opt, 1991; 11: 172-5; Psychol Med, 2001; 31: 949-64).
This fluorescent flicker can even affect behaviour. When six autistic children were observed under incan-descent and fluorescent lighting, they spent significantly more time engaged in repetitive behaviour under the fluorescents, attributed by the authors to the flicker (J Autism Child Schizophr, 1976; 6: 157-62).
A 1973 study by frontier light researcher Dr John Ott in a Sarasota, FL, school linked cool-white fluores-cent lighting to nervous fatigue, irritability, lapses of attention and hyperactivity (Ott JN. Lecture to the Society for Clinical Ecology, 1974). These effects, however, may not be due to flicker, but to the quality of the light itself, its overall colour appearance (known as 'spectral power distribution', or SPD). When the Florida school replaced its fluorescent lights with 'full-spectrum' fluorescents-said to mimic the SPD of natural daylight-a marked improve-ment in behaviour was seen. The children became calmer, more inter-ested in their work and paid more attention (Ott JN. Lecture to the Society for Clinical Ecology, 1974). Similar results were seen in experiments in two schools in California.
Modern fluorescent lighting
Is the new fluorescent lighting safe? According to Alasdair Philips of Powerwatch, fluorescent lighting has come a long way since this early research was done. "Modern fluores-cent lighting generates far less UV radiation than the old-fashioned bulbs, emits a broader spectrum of light, and is virtually flicker-free," he says. "However, until more research is done on this new technology-including CFLs-we just don't know for sure if it's safe."
Some preliminary research on modern fluorescents is reassuring. Electronic high-frequency ballasts, which control the flow of current, have mostly replaced the old-style magnetic ballasts and produce dramatically less flicker. They have been shown to reduce eye strain, headache and other vision symptoms (Lighting Res Technol, 1995; 27: 243-56). In one study, conventional ballasts were associated with increased stress and decreased performance, while modern electronic ones were not (Ergonomics, 1998; 41: 433-47).
Nevertheless, other research on contemporary fluorescents has not been so positive. One study found that indoor light sources, including fluores-cent, quartz halogen and even tung-sten-filament incandescent lamps, emitted surprising levels of "carcino-genic UV" radiation (Photochem Photobiol, 2004; 80: 47-51).
All of the fluorescents examined-including CFLs-gave off UVA rays, and many emitted UVB in wavelengths as short as 280 nm, shorter than the UVB present in sunlight. Even standard low-watt incandescent bulbs were found to emit these shorter-than-sunlight wavelengths. The concern here is that little is known of the potential health hazards of this type of radiation.
Although UV emissions are usually attenuated if the bulbs are shaded or covered, the researchers noted that, if they are not completely filtered, then "potentially harmful UV radiation may well be present."
The study's main concern was how this type of radiation affects photo-sensitive individuals (see box, page 20). However, the findings also have wider implications: "If wavelengths shorter than those in sunlight are present, exposed skin may accumulate adverse effects over time that are of concern not only for photosensitive individuals but also for the general population."
What to do
If you buy (or, indeed, are forced to buy) CFLs, Alasdair Phillips offers the following tips:
- Look for bulbs with a warm whiteor yellow tint as they trap more UV radiation.
- Make sure that the bulb has a filter; some of the cheaper versions don't.
- Check that the CFL uses a high-frequency electronic ballast.
A better option, however, would be full-spectrum fluorescent lighting, said to have the same spectral qualities as natural daylight. Compared with CFLs, there has been a considerable amount of research into this type of lighting-with positive results. As the late Dr Ott said in his book Health and Light (Ariel Press, 1973), full-spectrum lighting can improve classroom and work performance, boost immune function, and possibly lower the risk of diseases such as cancer, osteoporosis and even tooth decay.Full spectrum lighting is available from FSL Ltd (tel: 01494 883 328) and www.fullspectrumsolutions.com.
Allergic to light
A number of health conditions can give rise to light sensitivity, including the autoimmune disorder lupus, the genetic disorder xeroderma pigmentosum (UV sensitivity), and skin conditions such as erythropoietic protoporphyria and polymorphous light eruption. Prescription drugs, including sulphonamides, tetracycline and thiazide diuretics, can also cause hypersensitivity to light.
The photosensitive reaction is usually brought on by sunlight, but fluorescent lamps-at intensities used in interior lighting-can also trigger a response (Br J Dermatol, 1973; 89: 351-9, Br J Dermatol, 1969; 81: 420-8). Both UVA and UVB radiation from fluorescents have been implicated (Ann Rheum Dis, 1994 June; 53: 396-9; Ann NY Acad Sci, 1985; 453: 317-27). New research shows that even incandescent lamps may put photosensitive individuals at risk (Ergonomics, 1998; 41: 433-47).
Symptoms of photosensitivity may include a pink or red skin rash with blotchy blisters, scaly patches or raised spots on exposed areas. These may itch or burn and last for several days. More serious reactions, however, include the possibility of abnormally low blood pressure and loss of consciousness (Psychol Med, 2001; 31: 949-64).
One way that photosensitive individuals can protect themselves is to make sure that the lamp is fitted with a diffuser. In a study of patients with lupus, standard acrylic diffusers absorbed UVB radiation, and their use was asso-ciated with almost no patient-reported problems (Arthritis Rheum, 1992; 35: 949-52). Nevertheless, this may not eliminate the risk for all individuals.
CFLs: environmentally safe?
Compact fluorescent light bulbs (CFLs) contain the potent toxic metal mercury (at least 5 mg per light) as well as a variety of volatile organic compounds (VOCs) and other chemical pollutants from electronic components. This means they require special disposal. The law says that fluorescent lamps need tobe treated as toxic waste electrical and electronic equipment (WEEE), and collected by councils or taken to recycling sites. Still, it is likely that many will just be thrown into the dustbin, causing toxic pollution.
Indeed, Cameron S. Lory, chief author of a new report released by INFORM, a US non-profit environmental outreach organization, states: "Mercury from broken and discarded fluorescent lamps is a major contributor to widespread mercury contamination of the environment."